The invention relates to a double silo with an inner silo part and an outer silo part which surrounds it in an annular manner and is separated from it by a basically vertical silo dividing wall, and with an annular, aerated emptying chamber at the bottom of the inner silo part for the silo area formed in the outer silo part which emptying chamber is connected to the silo area by a plurality of openings in the silo dividing wall near the bottom.
In a known double silo of this type (DE-OS 30 15 068), incorporated herein by reference, the inner silo part has annularly running sloping surfaces under which the annular emptying chamber for the outer silo area is located. This is intended to create good conditions for removal in the outer silo area which are just as advantageous as those in the inner silo area, the removal devices of which are centrally located.
The prior art silo is not intended to have a mixing operation, which can be recognized, among other things, from the fact that no mixing chamber is associated with the inner silo area and that the annular emptying chamber for the outer silo area has neither the capability of being heavily aerated, which would be necessary for mixing the material in a mixing chamber, nor the height required for the volumetric expansion of the material in the process of being admixed in a mixing chamber. In other words, the prior art emptying chamber is not a mixing chamber, because the term mixing chamber denotes a non-tension emptying chamber which is added onto the outlet side of a silo area and has such a height and high aerability that the material removed from the silo not only simply passes through this chamber but is also rotated and uniformly mixed in a considerable volume in it by zones of differing aeration, see (DE PS 15 07 888) for instance, also incorporated herein by reference. Such mixing chambers are therefore also designated as uniform mixing chambers. Nevertheless, the double concentric silo, initially mentioned, has proven to be especially advantageous, among other reasons, because it combines a good emptying capacity of both silo areas with good static qualities. While the arrangement of several volumetric cells over each other can normally result in considerable problems in structures with such a high static stress as silos, in this known double silo the annular emptying chamber for the outer silo area is created under the inwardly sloping surface of the inner silo area without this causing a deterioration of the static conditions in the area of the silo bottom, because the sloping surfaces in the inner silo area have to be provided in any case and the central bottom area of the inner silo area can be set directly on the undisturbed ground or on the main silo bottom.
The invention has the task of creating such a silo arrangement in which mixing chambers are added to the outlet silo of the two silo areas.
Since mixing chambers must be considerably larger than the emptying chambers initially mentioned, and, in distinction to the known arrangement, not only the outer, but also the inner silo area should be provided with such a chamber, the solution of the task of the invention cannot presuppose static conditions which are as advantageous as those extant in the known silo arrangement.